Week 4 lecture: flower parts and pollinators

Question 1

Early gymnosperm sperms

Answer 1

flagellated (ginkos and cycads)

difference: don’t have to wim through WATER they swim through pollen tubes

Question 2

Pollen tube

Answer 2

for sperm transfer (gymnosperms and on)

point at which we’ve broken free of needing standing water/films of water.

Question 3

Major difference between gymnosperms and angiosperms- what makes gymnosperms unique?

Answer 3

cones for reproduction in gymnosperms (naked ovules); early versions still have flagellated sperm.

conifers similar to angiosperms in some ways. no flagellated sperm. Lack most other repro structures of flowering plants.

Confiers DO NOT have double fertilization; do not have a secondary covering for their seeds “naked seeds”

angiosperms: double fertilization. Have another seed covering

Question 4

What are gnetophytes?

Answer 4

like ephedra, wellwitchia. Important gymnosperms.

Have double fertilization (twin seeds)

Just about as old as angiosperms

Question 5

What did darwin call the abominable mystery?

Answer 5

the rapid development of higher plants (angiosperms)

They underwent massive adaptive radiation, appear to have been around 140 mya.

There’s a gap during the jurassic period and then all the sudden there’s gnetales and flowering plants.

Question 6

Name the two specialized structures of the flowering plants.

Answer 6

pistil and anthers (mega and microgametophytes)

Question 7

Pistil, ovules, and vessel seeds are unique to..

Answer 7

angiosperms

Question 8

how do we think gametophytes evolved?

Answer 8

leaf modification

microsporangium evolved to leave the spores (pollen) on the outside of a tightly wound leaf.

megasporangium evolved to wrap the ova inside, fuse along a suture and become a “conduplicate carpal” Seam holds ovules

Question 9

Can you tell angiosperm and gymnosperm pollen apart?

Answer 9

Yes. gymnosperms look like balloons for travel. Angiosperm are highly modified and convoluted.

Question 10

There can be tracheids and vessel elements for gymnosperms, angiosperms, and gnetales. What’s the normal distribution?

Answer 10

Gymnosperms= tracheids.

gnetales; most angiosperms= tracheids and vessel elements

early angiosperms only have tracheids.

additional pipe of vascular elements

Question 11

Describe a gymnosperm leaf; contrast it with an angiosperm leaf.

Answer 11

gymnosperms have dichotomous venation= every vein splits to 2, not parallel like monocots.

angiosperms= parallel veins (monocots) OR net veins (cross a lot, dicots)

note: highly modified needle-like leaves
exception: gnetum, has netty leaves; morphologicaly it’s very similar to angiosperms.

Question 12

morphological data and molecular data suggest what about the relationship between gymnosperms and angiosperms?

Answer 12

that we know nothing.

cycads: pretty different. potentially closest relative (molecularly)
morphologically: gnetum, ephedra, and welwitschia are most similar (ALL HAVE NECTARIES)

Question 13

angiosperms are far more diverse than..

Answer 13

gymnosperms (re less than an order of magnitude than angiosperms

only more successful group is insects. most successful on the planet.

fragmentation and isolation probably led to this diversity.

Question 14

How did plants drive animal/insect diversification?

Answer 14

mutualisms

rise of flowering plants is associated with the diversification of lots of other species.

Question 15

What species REALLY increased its diversity with the appearance of angiosperms?

Answer 15

butterflies.

Bees and wasps were already diversifying

Question 16

Earlist angiosperm reproductive structure; what did flowers look like?

Answer 16

bracts, bracteoles

Wasn’t trying to attract animals, trying to protect its reproductive bits.

early on arms race

Question 17

Evolutionary sequence of angiosperm reproductive structures

Answer 17

heavy bracts that protected flower first. + repro bits

bracts + tepals (probably also for protection)+ reproductive bits

” “ + sepals + petals + repro bits (100 million years ago); switch from antagonistic relationship to a mutualism with animals.

at this point they also developed nectaries as rewards

gnetales was around way before the evolution of angiosperm nectaries= consistant with independent evolution

Question 18

Flower: how is it made?

Answer 18

determinant tip of a branch

modified for repro; no longer has indeterminant growth

modified leaves (initially protection, then attraction)

Shortened internodes to the point that the nodes are in the same plane. Still have same whorls. ovules at the center, then andrecium, then petals, then sepals.

“Protection, attraction, male, female at the center”

Question 19

Specific flower parts:

what holds the flower to the stems?

Answer 19

Peduncle (main stem of an inflorescence)

pedicel (individual flower)

Question 20

Specific flower parts:

receptacle

Answer 20

swollen stem, provides a port? for the flower to sit on

internodes just got shorter and shorter

Question 21

Specific flower parts: sepals

Answer 21

remnants of heavy protective bracts usually.

1st whorl. 1 sepal. usually green

Question 22

Specific flower parts: sepal and petal

Answer 22

sepal: much larger and flashier. First thing you encounter.

Petals: bright bits, always the next bits though.
highly modified usually for attraction.

Question 23

Specific flower parts: Perianth

Answer 23

all parts of the flower that aren’t sexual

calyx and corolla (sepals and petals)

Question 24

Specific flower parts: calyx

Answer 24

all sepals together

Question 25

Specific flower parts: corolla

Answer 25

all petals together

Question 26

Specific flower parts: tepals

Answer 26

identical petals/sepals

Question 27

Specific flower parts: androecium

Answer 27

boy bits Anther (pollen grains) Filament have different ways to release pollen; may be modified highly.

Question 28

Specific flower parts:gynecium

Answer 28

pistil Stigma, style, ovaries. Stigma receives pollen.

Question 29

Specific flower parts: fruits

Answer 29

mature ovaries that contain seeds. only flowering plants have these.

Question 30

Specific flower parts: Carpel

Answer 30

stima, style, ovary, ovules (yeah.)

Question 31

Wind pollination: how do the girl and boy bits look

Answer 31

``` Anthers exerted (available to wind) produce copius amounts of pollen ``` female flowers stigma tend to be large and feathery - increase surface area - inconspicuous; no E into coloring - hang down, sway in the wind. ex. corn silk; lots of things to hang out.

Question 32

Describe inflorescence pollination

Answer 32

It's the same effort as making a big-ass flower, except you can get tons of pollinators and utilize the genetic diversity that your offspring will get from this. Ex. sunflower composite head. Inflorescence where corollas are reduced. Achenes are the fruits. Disc flower: reduced center that are radially symmetrical. Ray flowers: have the single petal Can be discs, rays, or both.

Question 33

Characteristics of flowers that are BAT pollinated.

Answer 33

strongly scented white (bloom at night) lot of support structures exposed at the top prolific nectar producers (not much pollen) pollen dusts bat's head.

Question 34

Characteristics of flowers that are MOTH pollinated

Answer 34

Night blooming White Papery big corollas (lack support structure) sickly sweet scent Tubular; nectary at the bottom to prevent other things from feeding. ---tubular florals hawk-moth pollinated: produce TONS of nectar because they have high energy needs.

Question 35

Characteristics of flowers that are fly pollinated

Answer 35

Carrion feeders: have specific flowers. Smell and look like rotting flesh Not brightly colored Some deceitful mimicry

Question 36

Characteristics of beetle pollinated flowers.

Answer 36

Not showy. Small, fleshy corollas, green and white. Robust, well-protected (heavy sepals and petals) Scented but not "floral scented" Produce nectar and pollen

Question 37

Characteristics of bee pollinated flowers

Answer 37

Red or brightly-colored. Big flower with no scent Odorless Hummingbird flowers are often upside-down with LONG tubular corollas accessory structure for perch of other birds (modified twigs)

Question 38

Characteristics of flowers that are butterfly pollinated.

Answer 38

pink, lavender color scented slightly robust flower for landing nectar rewards narrow corollas

Question 39

Bee pollinated flower characteristics: Disc-shaped flowers

Answer 39

Most bee pollinated flowers are astrocee (sunflower type inflorescences) ``` Disc-shaped flowers: no long corolla tube LOTS of pollen, or pollen+nectar slight scent yellow/blue flower pollen or nectar UV guides ```

Question 40

Bee pollinated flower characteristics: bell-shaped flowers

Answer 40

heavy pollen producing, usually blue color. bee gets all up in there.

Question 41

Bee pollinated flower characteristics: buzz pollinated

Answer 41

Big stamen, heavily pollinated. no external pollen presentation frequently pointing downward

Question 42

Fly pollinated flower characteristics: wax-gathering

Answer 42

some flowers produce wax that flies use for courtship rituals. type of orchids do this.